<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

<div style="background: skyblue;padding: 20px;position: absolute;">

</div>
<script type="text/javascript" src="js/util.js"></script>
<script>
    document.onmousemove = function (ev) {

        var oEvent = ev||event;
        var pos = getPos(oEvent);
        var oDiv = document.getElementsByTagName('div')[0];



        oDiv.style.left = pos.x+'px';
        oDiv.style.top = pos.y+'px';

    };

</script>
</body>
</html>